__________ invented the whistle that generated high frequency sounds above the range of human hearing
galton
________ observed that bats navigate in the dark using high frequency echo location
spallanzani
________ invented the hydrophone, the basis for naval pulse-echo sonar
langevin
_______ was the first detect gallstones with ultrasound
ludwig
_______ determined that frequency changes with motion
doppler
________ detected brain tumors with ultrasound
dussik
______ discovered that when certain crystals are deformed they produce electricity and when electricity is applied to the crystal the crystal deforms (vibrates)
currie
what is the name of the effect in question 7?
piezoelectric effect
____________ and ___________ used cattle tanks to produce ultrasonic images (water path scanner)
homes and howry
with B mode (greyscale) imaging the depth of the reflector is determined by the _________ it takes for the echo to return
time
the mathematical formula that the machine uses to determine the depth of a reflector is:
Depth = (rate x time) / 2
with B mode (greyscale) imaging the brightness of a dot placed on the screen is determined by the _________ of the reflection
intensity (strength)
distance is equal to ______ multiplied by ______
rate ; time
sound travels through soft tissues at a rate of ______ mm/us
1.54
how long does it take for sound to travel 2 cm and back through soft tissues
26 us
_______ is a format in which each pulse travels in the same direction from different starting points
linear
__________ is a format in which each pulse originates from the same starting point but goes out in different directions
sector
in color doppler, the color assigned to the top half of the color bar indicates that blood i flowing towards the transducer
TRUE
in color doppler, the darker shades of color indicate slower areas of flow
TRUE
a doppler shift can be represented by sound, a waveform or color
TRUE
a decrease in one variable results in an increase in related variable means that the variable are _______ proportional
indirectly
an increase in one variable results in an increase in related variable means the variables are _______ proportional
directly
984158
9.8 x 10 (5)
0.000962
9.6 x 10 (-4)
centi
hundredths
milli
thousandths
+6db increases the intensity _____ times the original
4x
-20db decreases the intensity ______ times the original
1/100
the log of 100 =
2
the log of 1000 =
3
giga
billion
mega
million
kilo
thousand
hecto
hundred
deca
tens
deci
tenth
centi
hundredth
milli
thousandth
micro
millionth
nano
billionth
+3dB =
2x
+6db increases the intensity ____ times the original.
4x
+9 dB =
8x
+10dB =
10x
+20dB =
100x
-3dB=
02-Jan
-6db=
04-Jan
-9 db=
08-Jan
-10db =
10-Jan
-20dB=
1/100